This book gives an overview of the epidemiological methods used to research the effects of electromagnetic fields (EMFs) on human health. The first part of the book introduces epidemiological concepts and principles, providing appropriate examples and tips for practical usage. The second part details the state of scientific knowledge for some controversial issues in EMF research, while the third part considers how novelty, the steep increase of radiofrequency (RF) EMF exposure from wireless communications, and other challenges affect risk assessment today.